Rays Prospects: Wade Davis versus Desmond Jennings

[Shelton Southpaw]

Question, who out of Davis & Jennings do you feel will have more of an impact at the Major League level?
I see that Davis is ranked higher on the Rays prospect list, but am not sure how good he will be in the Major leagues.

Since I just added Clayton Kershaw to my minor leaugue roster, before his start on Sunday, I was thinking of adding either Wade Davis or Desmond Jennings to fill my final minor league roster spot.
I also had just added Jason Heyward to my minor league roster due to an uneven player roster trade: I traded Delmon Young & David Price for Mark Texiera.

I know that the A's have 2 good pitching prospects in Brett Anderson & Trevor Cahill as well.

Please let me know your thoughts about these players and who you would choose.

Thanks